Keynote: Aspects of fractionation

All higher organisms have whole genome duplications (WGD) somewhere in their evolutionary history, sometimes many of them. More than rearrangements such as inversion and translocation, WGD followed by fractionation causes a thorough shuffling of gene order. Fractionation [1] is the loss, sooner or later, of one of almost all the pairs of duplicate genes created by WGD. As a result, what was single set of of genes ordered on one ancestral chromosome is now partitioned, in an interleaving pattern [2], among two different chromosomes. Comparing the resulting genome to its ancestor or to the genome of a related species that escaped the WGD reveals a greatly rearranged gene order relatively quickly on the evolutionary time scale.